Types of cookies used by Google

We use different types of cookies to run Google websites and ads-related products. Some or all of the cookies identified below may be stored in your browser. You can view and manage cookies in your browser (though browsers for mobile devices may not offer this visibility).

Category of use

Example

Preferences

These cookies allow our websites to remember information that changes the way the site behaves or looks, such as your preferred language or the region you are in. For instance, by remembering your region, a website may be able to provide you with local weather reports or traffic news. These cookies can also assist you in changing text size, font and other parts of web pages that you can personalise.

Loss of the information stored in a preference cookie may make the website experience less functional but should not prevent it from working.

Most Google users will have a preferences cookie called ‘NID’ in their browsers. A browser sends this cookie with requests to Google’s sites. The NID cookie contains a unique ID that Google uses to remember your preferences and other information, such as your preferred language (e.g. English), how many search results you wish to have shown per page (e.g. 10 or 20) and whether or not you wish to have Google’s SafeSearch filter turned on.

Security

We use security cookies to authenticate users, prevent fraudulent use of login credentials and protect user data from unauthorised parties.

For example, we use cookies called ‘SID’ and ‘HSID’ which contain digitally signed and encrypted records of a user’s Google account ID and most recent sign-in time. The combination of these two cookies allows us to block many types of attack, such as attempts to steal the content of forms that you complete on web pages.

Processes

Process cookies help make the website work and deliver services that the website visitor expects, like navigating around web pages or accessing secure areas of the website. Without these cookies, the website cannot function properly.

For example, we use a cookie called ‘lbcs’ which makes it possible for Google Docs to open many Docs in one browser. Blocking this cookie would prevent Google Docs from operating correctly.

Advertising

We use cookies to make advertising more engaging to users and more valuable to publishers and advertisers. Some common applications of cookies are to select advertising based on what’s relevant to a user; to improve reporting on campaign performance and to avoid showing ads that the user has already seen.

Google uses cookies like NID and SID to help customise adverts on Google properties, such as Google Search. For example, we use such cookies to remember your most recent searches, your previous interactions with an advertiser’s adverts or search results and your visits to an advertiser’s website. This helps us to show you customised adverts on Google.

We also use one or more cookies for advertising that we serve across the web. One of the main advertising cookies on non-Google sites is named ‘IDE‘ and is stored in browsers under the domain doubleclick.net. Another is stored in google.com and is called ANID. We use other cookies with names such as DSID, FLC, AID, TAID and exchange_uid. Other Google properties, such as YouTube, may also use these cookies to show you more relevant adverts.

Sometimes advertising cookies may be set on the domain of the site that you're visiting. In the case of advertising we serve across the web, cookies named ‘__gads’ or ‘__gac’ may be set on the domain of the site that you're visiting. Unlike cookies that are set on Google's own domains, these cookies can't be read by Google when you're on a site other than the one on which they were set. They serve purposes such as measuring interactions with the ads on that domain and preventing the same ads from being shown to you too many times.

Google also uses conversion cookies whose main purpose is to help advertisers determine how many times the people who click on their adverts end up purchasing their products. These cookies allow Google and the advertiser to determine that you clicked on the advert and later visited the advertiser site. Conversion cookies are not used by Google for personalised ad targeting and persist for a limited time only. A cookie named ‘Conversion‘ is dedicated to this purpose. It's generally set in the googleadservices.com domain or the google.com domain (you can find a list of domains that we use for advertising cookies at the foot of this page). Some of our other cookies may be used to measure conversion events as well. For example, DoubleClick and Google Analytics cookies may also be used for this purpose.

We also use cookies named 'AID', 'DSID' and 'TAID', which are used to link your activity across devices if you’ve previously signed in to your Google Account on another device. We do this to coordinate that the ads you see across devices and measure conversion events. These cookies may be set on the domains google.com/ads, google.com/ads/measurement or googleadservices.com. If you don't want the ads that you see to be coordinated across your devices, you can opt out of Ads Personalisation using Ads Settings.

Session State

Websites often collect information about how users interact with a website. This may include the pages users visit most often and whether users get error messages from certain pages. We use these so-called ‘session state cookies’ to help us improve our services, in order to improve our users’ browsing experience. Blocking or deleting these cookies will not render the website unusable.

These cookies may also be used to anonymously measure the effectiveness of PPC (pay per click) and affiliate advertising.

For example, we use a cookie called ‘recently_watched_video_id_list’ so that YouTube can record the videos most recently watched by a particular browser.

Analytics

Google Analytics is Google’s analytics tool that helps website and app owners to understand how visitors engage with their properties. It may use a set of cookies to collect information and report website usage statistics without personally identifying individual visitors to Google. The main cookie used by Google Analytics is the ‘_ga’ cookie.

In addition to reporting website usage statistics, Google Analytics can also be used, together with some of the advertising cookies described above, to help show more relevant ads on Google properties (like Google Search) and across the web and to measure interactions with the ads we show.